In the background of this disclosure, there is a developing cartridge that is detachably mounted to an image forming apparatus, and the developing cartridge has a developing frame accommodating toner therein, a developing roller carrying the toner thereon and a blade assembly regulating a layer thickness of the toner carried on the developing roller.
In the above developing cartridge, the developing frame has a lower frame that rotatably supports the developing roller and an upper frame that is welded to the lower frame. The developing frame is formed with an opening set by a front end portion of the upper frame and both sidewalls and a bottom wall of the lower frame. The developing roller is arranged to face the opening.
The blade assembly is fixed to an upper side of the upper frame so that a contact part thereof contacting the developing roller is arranged between the opening and the developing roller.